1. Field of the Invention
The present invention relates generally to memory cards, and more particularly to a memory card (e.g., a multi-media card or secure digital card) comprising a semiconductor device module which is configured to be interfaced to an external case having first and second covers movably attached thereto for selectively exposing the I/O pads or contacts and the test features/pads of the module.
2. Description of the Related Art
As is well known in the electronics industry, memory cards are being used in increasing numbers to provide memory storage and other electronic functions for devices such as digital cameras, MP3 players, cellular phones, and personal digital assistants. In this regard, memory cards are provided in various formats, including multi-media cards and secure digital cards.
Many memory cards include a module which itself comprises a printed circuit board (PCB) having a conductive wiring pattern disposed thereon. Attached to one side or surface of the PCB and electrically connected to the conductive pattern thereof is a plurality of electronic circuit devices, such as semiconductor packages, semiconductor dies, and/or passive elements. These electronic circuit devices and a portion of the PCB are often covered or encapsulated by an encapsulant material. The PCB also includes a plurality of input/output (I/O) pads disposed on the side or surface thereof opposite that having the electronic circuit devices thereon. These I/O pads are not covered by the encapsulant material, and thus are exposed in the completed module which comprises the PCB, the electronic circuit devices and the encapsulant material. Attached to the module is a skin or case of the memory card, such case generally defining the outer appearance of the memory card. The module is coupled to the case such that the I/O pads disposed on the PCB are not covered by the case, and thus remain exposed in the fully assembled memory card. These I/O pads of the memory card provide an external interface for an insertion point or socket. The completed memory card has a generally rectangular configuration, with most memory cards including a chamfer formed at one edge thereof which is adjacent to the I/O pads.
As indicated above, the I/O pads of the memory card are exposed to allow for the transmission and receipt of signals between the memory card and an external device. Because they are exposed, the I/O pads are susceptible to short-circuiting as a result of coming into contact with conductive substances, such short circuiting carrying the risk of varying or deleting the data stored within the memory card. In order to avoid such risk, some currently known memory cards include a separate lower case on which a guide block is formed. However, even in those memory cards including a guide block, there is still a possibility that a short circuit may occur among the plurality of I/O pads. For example, a memory card having a guide block is still susceptible to a short circuit occurring as a result of conductive substances or structures which are not of a fixed shape (e.g., are flexible) coming into contact with the I/O pads. As previously explained, such a short circuit may alter or delete data within the onboard electronic circuit devices of the memory card.
Further, after assembly, memory cards as currently known in the art are tested to confirm whether or not the circuit is open. The I/O pads are commonly used for performing the test. However, completing this testing using the I/O pads usually takes a long time, particularly when the number of I/O pads is small. This is because a limited number of I/O pads must be used to test the entire memory card. As a result, some currently known memory cards also include a number of test pads or features that are separately formed on the memory card module and initially exposed in the memory card. These test pads/features are adapted to be used during the testing process to shorten test time. However, these test pads/features, if included in the memory card, provide the same shorting risk as do the I/O pads, and therefore must typically be covered with a layer of tape after the completion of the test. The present invention provides a memory card which is uniquely configured to include first and second covers movably attached to a case thereof for selectively covering or exposing the I/O pads and the test features/pads of the module of the memory card.